Indiana farmers harvested 650,000 acres
(263,000 ha) of SRWW in 1998, at an average yield of 55 bu/acre
(3,451 kg/ha), for a total production of 35.75 million bushels
(0.907 million metric tons). Total production in 1998 was 93.3
% of the production in 1997. Patterson, in its second year of
production, was the leading public cultivar, occupying 16.7 %
of the wheat area, up from 9.4 % of the wheat area in 1997. Public
cultivars, identified by cultivar name, occupied 36.5 % of the
wheat area; private cultivars and brands, including some publicly
developed lines marketed under license agreements, occupied 63.5
% of the wheat area.

Cultivars.

Five SRWW cultivars were released. Seed of these new cultivars
will be available to farmers for planting in autumn 1999. Their
temporary breeding designations are shown in parentheses, and
their most important traits are listed. Goldfield (P89118RC1-9-3-3)
heads 3 days later than Patterson at Lafayette , has low incidence
of FHB, has resistance to glume blotch, and is very winterhardy.
INW9811 (P86958RC4-2-1-10) heads early like Patterson at
Lafayette, has resistance to glume blotch, and has Hessian fly
resistance-gene H13. INW9853 (P88288C1-6-1-2) heads
4 days later than Patterson, has low incidence to FHB, and has
resistance to glume blotch. INW9812 (P88288A1-15-1-4) heads
early like Patterson and has glume blotch resistance. INW9824
(P92823A1-1-4-4-5) heads 1 day later than Patterson and has one
gene for type 2 resistance to FHB from cv Ning 7840.

Weather and disease summary.

Wheat seeding normally is completed by the
end of October, but continued through November 1997 because of
warm temperatures. Wheat, normally dormant by early December,
grew until the end of December, resulting in more than optimal
growth in wheat seeded in early to mid October. Temperatures throughout
the winter months were unusually warm due to the influence of
the El Niño weather pattern. Wheat resumed growth by late
February, 2 to 3 weeks earlier than normal, and continued to be
at least 2 weeks earlier than normal to harvest. Crop growth was
excellent early in the season, but by early June, the crop condition
began to decline due to excessive moisture and diseases, particularly
powdery mildew and glume and leaf blotches. Fusarium head blight
was moderate to severe in many areas in southern Indiana but was
negligible generally north of Indianapolis. Grain test weight
and quality were reduced by diseases and rainy weather in some
areas of Indiana during harvest.

Barley yellow dwarf virus.

H.C. Sharma, J.M. Anderson, and H.W. Ohm.

ELISA of hybrids between our BYDV-resistant addition lines, P25
and P114, and the Th.intermedium addition line
L1 developed in France, showed that these most likely have the
same genes, because the ELISA values of the hybrids were the same
as those of the disomics. However, dot blot analysis of the lines
and chromosome pairing in the hybrids showed that the group-7
chromosome from Th. intermedium in L1 is not the
same as the one in the Purdue lines. Probe pAW161, which specifically
hybridized to the long arm telomere of the Th. intermedium
chromosome in P29, hybridized to genomic DNA of P29, but not
to genomic DNA of wheat or L1. The hybrids averaged 1.21 to 2.09
univalents per cell.

To determine if there is enhanced resistance to PAV isolates of
the virus exists in hybrids among group 7, group 2, and group
1 chromosomes of Th. intermedium, hybrids among
these addition lines were produced. Simultaneously, seeds of monosomic
addition lines for groups 2 and 1 were produced and irradiated
to induce translocations.

Anther culture and interspecific crosses of wheat with alien species
for Hessian fly resistance were carried out by H. Sharma in cooperation
with Dr. Ouafae Benlhabib in Morocco.

Evaluation by ELISA of 56 El.elongata and six El.pontica accessions demonstrated that these were resistant
to P-PAV and RPV BYDV isolates.

Preliminary studies of translocation lines derived from the BYDV-resistant
P29 line have indicated that several of these lines contain multiple
translocations that can be separated through crosses to susceptible
wheat lines. Wheat lines that are resistant to BYDV and contain
a minimal amount of wheatgrass DNA should be possible to obtain.

Facilitating the effort to incorporate BYDV resistance into elite
material, a telomere repetitive sequence was identified that cosegregates
with the wheatgrass-derived BYDV resistance. A rapid PCR-based
test was developed as a marker-assisted selection tool for identifying
BYDV resistant plants without the need for the standard virus
inoculation and detection method.

DNA library.

I.M. Dweikat and H.W. Ohm.

We are in the process of constructing a BAC library in the A-genome
progenitor T. urartu. The isolated high- molecular
weight DNA was embedded in agarose microplugs. The plugs were
digested with EcoRI plus EcoRI methylase at a ratio
of 1:20. To date, we have available at least 30,000 clones that
contain inserts ranging in sizefrom 50 to 230 kb, with an average
of 110 kb. Our goal is to have at least 150,000 clones, giving
us 3 X coverage of the diploid T. uartu genome.

Septoria leaf blotch.

S. Goodwin.

We are continuing to analyze the genetics of the S. tritici
blotch pathogen, Mycosphaerellagraminicola. Previous
work identified three RAPD loci with size-variable amplification
products. Alleles at each locus were cloned and sequenced and,
in each case, the polymorphism was due to a single deletion of
2060 base pairs. Primers were developed to amplify across the
size-variable region at each locus, yielding SCAR markers for
each locus. These markers can be used to characterize populations
of M. graminicola in the field. To identify more
markers, we are attempting to convert a DNA-fingerprint probe
for M. graminicola (developed by Bruce McDonald)
into SCAR-type markers. The goal is to develop a minimum of 810
SCAR markers for analyzing the population genetics and epidemiology
of this organism.

More than 100 RAPD loci, including the SCAR markers, were placed
onto a genetic map of M. graminicola prepared in
a collaborative project with Gert Kema (Wageningen, The Netherlands).
The final map will contain virulence, mating type, and over 300
AFLP markers developed by Dr. Kema plus our 100 RAPD and SCAR
markers.

Crosses were made to determine whether various genes for resistance
to Septoria tritici blotch in wheat are independent. F2
populations of the cultivar Sullivan (containing the Bulgaria
88 resistance gene) crossed with the cultivars IAS 20, Israel
493, and Veranapolis were tested with an Indiana isolate of the
Septoria tritici blotch pathogen. There was no segregation
in the 'IAS 20 / Sullivan' population, indicating that the genes
may be allelic, linked, or identical. Susceptible plants were
identified in the other populations, indicating that the resistance
genes in Israel 493, Veranapolis, and Tadinia are independent
from the gene in Bulgaria 88. Crosses between Israel 493 and Veranapolis
and Israel 493 and IAS 20 also yielded susceptible progeny, indicating
that these genes are independent from each other. However, the
number of susceptible plants in the 'Israel 493 / IAS 20' population
was smaller than expected. Additional tests are continuing during
the spring greenhouse season.

Work with resistance gene analogs from wheat is continuing, and
we have obtained genomic clones containing some of the resistance
gene analogs. We are now preparing to map the resistance gene
analogs to determine whether they are located near any known resistance
genes.

Differential display is continuing to identify genes expressed
in the resistant cultivar Tadinia in response to inoculation with
M. graminicola. A number of clones has been obtained,
one of which has some similarity to a pathogenesis-related protein
from legumes. Work to obtain additional clones is continuing.

For more information see my lab web site at: http://www.btny.purdue.edu/USDA-
ARS/Goodwin_lab/Goodwin_Lab.html.

Soilborne diseases.

D. Huber, D. Schulze, and I. Thompson.

Soilborne diseases continue to be important factors limiting the
yield and quality of wheat in Indiana. Take-all research has focused
on 1) the interaction of manganese oxidation as a virulence factor
in G.graminis var. tritici, 2) the role
of microorganisms in the rhizosphere that influence manganese
availability, and 3) the critical role of manganese as a micronutrient
in resistance and defense reactions of the wheat plant. Only isolates
of G.graminis var. tritici, which change
reduced manganese to the unavailable oxidized manganese (Mn^+2^
to Mn^+4^) are virulent onwheat. Isolates that are temperature
sensitive for virulence show the same temperature sensitivity
for manganese oxidation. Cultural practices and rhizosphere organisms
that oxidize manganese can predispose wheat to take-all or increase
the severity of take-all, and, conversely, organisms that reduce
manganese can reduce the severity of take-all and function in
biological control. Wheat cultivars efficient for micronutrient
uptake are tolerant to take-all. We have confirmed these interacting
effects during infection and pathogenesis by use of high energy
X-ray fluorescence techniques at the National Synchrotron Light
Source.

Potential biological control organisms are being evaluated against
take-all using a standardized protocol as part of the Southern
Regional Research Project on Biological Control. This research
has demonstrated that formulation of the product may be as important
in suppressing disease as any of the agents evaluated. Coöperative
research with the Ningxia and Gansu Institutes of Plant Protection
in Northwestern China on chemical, biological, and cultural controls
of take-all has been conducted the past 4 years and is continuing.
This coöperation has provided an opportunity to share ideas
and materials for more effective control of take-all and other
soilborne diseases.

Fusarium head blight.

G. Shaner and G. Buechley.

The resistance to scab in certain Chinese wheat varieties, which
are being extensively used as sources of resistance for U.S. breeding
programs, is thought to derive from Italian wheats. We searched
the GRIN database for wheats, both winter and spring habits, originally
collected from Italy.

Forty-two accessions were evaluated for FHB resistance. Selected
progeny from a preliminary screening were evaluated in the greenhouse
to confirm their resistance to F. graminearum. Plants
were inoculated by spraying the entire spike with a spore suspension
or by introducing a spore suspension into a central floret of
each spike. These two inoculation methods were intended to detect
different kinds of resistance (to initial infection or to spread
of the fungus within a spike).

In the initial test, we observed a considerable range in scab
severity among lines. The more striking result was the considerable
variation in amount of FHB among plants within accessions, indicating
considerable heterogeneity in resistance in the original germ
plasm accessions. Progeny of 19 accessions from the preliminary
test were selected for further evaluation in the autumn of 1997.
Although the second test represented lines from plants that appeared
to be resistant in the original test, there was still a wide range
in severity of head blight, for both the floret and spray inoculations.
The correlation between head blight severity for the parent plant
and the mean severity for the five progeny plants subjected to
spray inoculation was only 0.013. A similarly low correlation
was noted when data for the point inoculation of progeny plants
were analyzed.

Nonetheless, several of the lines in the second test had low mean
ratings for head blight, and the effect of lines in the analysis
of variance was highly significant. A poor correlation occurred
between severity for the spray and floret inoculations. Several
lines had low severity with both types of inoculation. This germ
plasm appears to have different kinds of resistance and, therefore,
different genes for resistance. The range in severity of head
blight among the lines suggests that several genes for resistance
may be represented in this material. Whether these genes differ
from those in the Chinese material remains to be determined.

We also tested lines from a Uniform Winter Wheat Fusarium Head
Blight Nursery, which includes lines from many wheat breeding
programs in the eastern soft wheat region. Tests were conducted
as described above for the Italian germ plasm. A weak correlation
between heading date and severity of FHB was noted, with later-maturing
wheats tending to be more resistant. Resistant lines were found
among the early-maturing wheats. Differences among lines in severity
of FHB were substantial, but most had less than the susceptible
check varieties, indicating that wheat breeders are making progress
in developing resistance to this disease. As noted in the Italian
wheat study, a poor correlation occurred between severity of head
blight following spray inoculation and following floret inoculation,
suggesting that different types of resistance are represented
in this germ plasm. A couple of lines were very resistant to floret
inoculation (resistance to spread of the fungus in the spike following
primary infection), butvery susceptible to spray inoculation (no
resistance to primary infection).

Research on Hessian fly.

Insect surveys. Uniform Hessian Fly Nursery (Cambron and
Ratcliffe). Twenty-two Hessian fly- resistant
wheat cultivars or germ plasm lines were evaluated in Uniform
Hessian Fly Nursery Trials in Alabama (5),Arkansas (1), Georgia
(3), Illinois (1), Indiana (3), and South Carolina (2). Hessian
fly infestations were too low to provide meaningful data in 1998
in all but two trials in Alabama (Baldwin and Hale Counties) and
Georgia (Griffin and Plains). At these locations, wheat entries
carrying Hessian fly resistance genes H7H8, H9,
H12, H13, H17, H18, H21, and
H26 were the most effective, although H9 was less
effective in the trial at Plains than at the other locations.
Twenty-two wheat lines or cultivars from the Uniform Hessian Fly
Nursery, and 34 wheat lines each from the Uniform Southern and
Uniform Eastern Soft Red Winter Wheat Nurseries were evaluated
for responses to Hessian fly biotypes GP, B, C, D, E, and L in
laboratory tests. The response of wheat lines to the Hessian fly
biotypes will be published in 1999 in the USDA, ARS, Special Report
"Hessian Fly Status Report for Crop Year 1998/99", available
from S. Cambron.

Alabama (Ratcliffe in cooperation with K. Flanders, Auburn
University). Hessian fly populations were collected from seven
locations in Alabama in 1998. Results of biotype tests with these
populations and three populations collected in 1997 demonstrated
that frequencies of the highly virulent biotype L ranged from
016 % in southern counties (Baldwin, Henry, and Washington); 033
% in central counties (Elmore, Hale, and St. Clair); and 5077
% in northern counties (Lawrence, Madison, and Marshall). Wheat
cultivars with H7H8 resistance should be effective against
fly populations in central and southern Alabama as a result of
the low to moderate level of biotype L in these areas. Data from
the Uniform Hessian Fly Nursery Trials in Baldwin and Hale Counties,
reported above, substantiated this conclusion.

Cultivar release (Cambron and Ratcliffe in cooperation with
H. Ohm). The development and release of the soft winter wheat
cultivar INW9811 in cooperation with Purdue University were significant
steps in improving Hessian fly control for wheat growers in the
southern mid-west and mid-south. INW9811 is the first wheat variety
to contain the Hessian fly-resistance gene H13 and to demonstrate
resistance to biotype L. INW9811 will be particularly useful to
growers in southern IL and IN, northeastern AR, northern AL, GA,
SC, and southern VA where present varieties are not effective
because of the high frequency of Hessian fly biotype L in field
populations.

Physiological parameters (Gumaelius and
Ratcliffe). Research was begun in
July, 1998, to investigate plant physiological responses in Hessian
fly-susceptible, resistant, and tolerant wheat when exposed to
biotype L at 18 and 26 C. Of particular interest are possible
changes associated with these responses by wheat plants that influence
chloroplast production, production and relative concentrations
of sugars, and cell structure. Physiological parameters were identified
and bioassay, chemical, and physiological methods were selected
for investigating the various parameters.

Hessian fly genetics (Shukle and Zantoko). The most cost-effective
and environmentally sound method of control of the Hessian fly
is through genetically resistant wheat. However, the use of resistant
wheat has resulted in the development of biotypes of the insect
that can overcome resistance. Our research is directed toward
understanding the molecular basis of how the fly overcomes resistance
as well as the development of molecular markers for analysis of
the genetic structure of fly populations. This knowledge is essential
for collaboration with wheat breeders to ensure effective and
durable control of the Hessian fly. We have identified AFLP markers
tightly linked to the locus controlling avirulence/virulence with
respect to resistance gene H13 in wheat. These markers
have been cloned and converted to SCAR markers. This approach
is being undertaken with respect to loci controlling the interaction
with other genes for resistance in wheat.

Molecular aspects of Hessian fly resistance (Williams, Collier,
and Liang). Hessian fly crosses were constructed to determine
whether virulence to the resistance gene H6 is due to the
same gene in virulent populations from across the U.S. Individual
Hessian flies from 10 H6-virulent populations were intercrossed
in pair- wise combinations. Results indicated that all H6-virulent
populations utilized the same virulence gene rather than accumulating
mutations in a biosynthetic pathway leading to the production
of an elicitor molecule. STS primers were designed as markers
for a new resistance gene to aid in its introgression, along with
other Hessian fly resistance genes, into a pyramided cultivar.
We further characterized a wheat gene was that is induced soon
after avirulent larvae begin feeding on seedlings. This gene is
present in about one copy per genome and is similar in the DNA
sequence to jasmonic acid-induced genes that may be involved in
systemic acquired resistance.

Avirulence genes (J. Stuart). The gene-for-gene relationship
between wheat and the Hessian fly wasinvestigated by molecular
genetic mapping of three X-linked avirulence genes, vH6,
vH9, and vH13, in the Hessian fly. These genes confer
avirulence to Hessian fly-resistance genes H6, H9,
and H13 in wheat. We used a combination of bulked segregant
analysis and two- and three-point crosses to determine the order
of these genes with respect to each other; the white eye mutation;
and three X-linked molecular markers, G15-1, 020, and 021. These
markers were developed from genomic lambda clones, G15-1, 020,
and 021, which were previously positioned on the polytene chromosomes
of the Hessian fly by in situ hybridization. Each avirulence gene
was found to reside on chromosome X1, but they were not clustered.
The gene order was determined to be vH9 - vH6 - G15 - 1
- w - vH13 - 020 - 021. The positions of lG15-1, l020,
and l021 on the polytene chromosomes of the Hessian fly salivary
gland established their orientation on Hessian fly chromosome
X1. These results are the best evidence to date that single corresponding
avirulence genes exist in the Hessian fly for each resistance
gene in wheat.

Personnel.

Ted Kisha, Ph.D. degree from Michigan State
University, joined the Small Grains Research Team in March 1998,
in the position of Research Associate in the Department of Agronomy.
Ted will focus on genetics of resistance to glume blotch caused
by Phaeosphaerianodorum. Ernie Cebert completed
the Ph.D. degree with H. Ohm and is on the faculty in the Department
of Plant and Soil Science at Alabama A & M University, Normal,
AL. Vanessa Cook completed the Ph.D. degree with H. Ohm and is
a maize breeder at DeKalb Genetics, Inc., Spencer, Iowa. Louis
Yang completed the Ph.D. degree with H. Ohm and is a maize breeder
at Asgrow Seed Company, 634 East Lincoln Way, Ames, IA. Xiaorong
Shen began studies toward the Ph.D. degree and Jim Uphaus began
studies toward the MS degree under the direction of H. Ohm.